1. Technical Field
The present disclosure relates to a power supply system, more particularly to a power supply system for an electronic device.
2. Description of Related Art
In a personal computer (PC) system, power management is adopted to conserve energy while the PC is in use and put the PC to sleep to save energy when the PC is not in use. System power states derive from the Advanced Configuration and Power Interface (ACPI) specification. They are defined as follows:
S0/Working—The CPU is fully up and running; devices are powered up and down as needed.
S1—The CPU is stopped; RAM is refreshed; the system is running in a low power mode.
S2—The CPU has no power; RAM is refreshed; the system is in a lower power mode than S1.
S3—The CPU has no power; RAM is in slow refresh mode; the power supply is generally in a reduced power mode (for example, it cannot supply much power and is running in a lower power efficiency mode).
S4—The hardware is completely off; system memory has been saved to disk.
S5/Off—the hardware is completely off; the operating system has shut down; nothing has been saved.
Usually, when the computer is retained in S5 state, it consumes less power than in other states. However, in conventional S5 state, some components of the computer still consume power which causes unnecessary waste.
Therefore, there is room for improvement within the art.